EG-CE 441 Environmental Engineering
Homework #4
(Due 10/29/2013)
1. (Problem 6-13) Determine the lime and soda ash dose, in mg/L as CaCO3, to soften the following
water to a final hardness of 80 mg/L as CaCO3. The ion concentrations reported below are all

Chapter 6 FE EXAM FORMATTED PROBLEMS
6-1.
Three parallel flow flocculation basins are to be used to treat a flow rate of 3 MGD. What
is the design volume, in cubic feet, of one of these tanks if the detention time is 30
minutes?
Parallel flow therefore,
Q